1. Field of the Invention
The invention relates to a low noise level control valve for use in high velocity flow applications.
2. Description of the Prior Art
The art in this field is believed to be best set forth in an article entitled "Liquid Control Valves" published in "Chemical Engineering" on May 6, 1972, p. 92-98.
As stated in the article, high velocity flow through valves frequently results in problems of erosion, erratic control, vibration, shutoff leakage and noise. The problem of noise is dealt with in detail in page 94 of the article.
Hydraulic and pneumatic valves of the type now in use frequently produce noise to an extent which may exceed legal limits. In pneumatic valves, this results primarily from aerodynamic noise caused by turbulence and shock waves due to the high velocity of the fluid flow.